In the electric utility industry, plug-in, socket-type watthour meters are commonly used to measure electric power consumption at residential or commercial sites. The most common type is more properly known as a kilowatt hour meter or a joule meter. When used in electricity retailing, the utilities record the values measured by these meters to generate an invoice for the electricity. These meters may also record other variables including the time when the electricity was used.
The socket for the watthour meter is usually installed in a housing that is mounted on a wall of the residence or commercial building. Typically, the housing is transparent or has a window so that the meter can be read without opening the housing. The meter socket contains pairs of line and load terminals which are respectively connected to electric line and load conductors. The terminals receive the blade contacts of a plug-in watthour meter to complete an electric circuit through the meter between the line and load terminals.
Meter sockets having locking jaws for receiving the bayonet or blade contacts of a watt-hour meter are well known. The meter jaws allow a meter to be quickly and easily installed and removed without the use of screws or other fastening devices. The meter opposing sides of the meter jaws are biased towards each other compressively engage the blade contacts of the meter.
Meter sockets are generally located on a panel or in an enclosure having openings in the side and/or end walls for receiving the line cables and the load cables. When the meter socket is mounted in an enclosure, it is typically mounted to a panel attached to the back wall of the enclosure. The enclosure has a removable front cover or door with an opening for receiving the dome portion of the meter, which extends therethrough when installed in the meter socket.
The meter socket generally includes four or six jaw-type terminals for receiving the blade contacts of the meter. As discussed in U.S. Pat. No. 3,281,550 to Waldrop, some meter sockets can also include bypass conductor members that are used to short the line and load contact of the same phase by operation of a lever. In this particular instance, the bypass conductor members are moved to an open position by placing an insulative material against the bypass member to move the cantilevered bypass member out of electrical contact with the load side jaw-type terminals.
A meter for measuring the usage of electricity is coupled to a plurality of bus members or lines at a meter socket. The meter socket includes a non-conductive base formed by one or more members, a plurality of lugs for connecting the bus lines, a plurality of pincer-like jaw assemblies (also referred to herein as a “meter jaw”), and a base bracket. Typically, the base bracket is attached to a grounding/support structure and the non-conductive base is attached to the base bracket. The lugs are attached to the non-conductive base member(s) and each of the jaw assemblies is connected to a lug. Thus, each jaw assembly is in electrical communication with either the line or the load bus. The jaw assembly openings face away from the front of the meter socket to allow easy insertion of the bayonet connectors (also referred to herein as blade connectors) of the meter. The meter typically includes a cylindrically-shaped enclosure containing a metering device with the meter display on the front side and a plurality of bayonet connectors extending from the back side. The bayonet connectors are adapted to be received by the jaw assemblies to electrically connect the line and load buses through the meter. The metering device collects data relating to electrical usage based on the amount of electricity passing through the meter.
The meter sockets that are currently in use (“the old types” or “prior art”)) are generally assemblies that include two mounting blocks attached to a steel support bridge, two stand-alone support blocks, a plurality of jaw assemblies and connectors and a plurality of screws, connectors and/or fasteners. Typically, these meter socket assemblies use two different types of connectors (45-degrees or 90-degrees depending of construction type) for the line and load connections. Moreover, these prior art designs with their numerous components and fasteners require a considerable amount of assembly time.
The old types of meter sockets typically have rectangular spacers that receive the meter jaw assemblies. These spacers fit into rectangular holes in the block and tend to slide from side-to-side. When a cable is installed in the cable receiving port and torque is applied to the retaining screw, a force is transferred to the body of the connector that causes the connector to move away from the block wall and can damage the block.
In addition, the two “old types” of connectors typically require three holes through the planar portion; one hole for receiving the jaws assembly and two holes that corresponded to dimples on the block. These additional two holes reduce the cross-section of the connector (i.e., the amount of material in the connector), which is carrying electrical current. The reduced cross-section means that the same amount of electricity must be carried by less conductive material, which is less efficient and increases the temperature of the connector.
The prior art meter socket described above, as well as other well known meter sockets, suffers a variety of disadvantages. Accordingly, there is a need for a meter socket with unitary construction (i.e., a “mono-block” or a “uni-block”) that doesn't use a steel bridge to connect the two mounting blocks and doesn't require fasteners or screws to attach the stand-alone support blocks. There is also a need for a meter socket that is designed to receive a jaws assembly so that it does not slide when the retaining screws are torqued to secure the line and load cables.
There is also a need for a meter socket that can use connectors for the line and load connections that only require one hole so that they will more efficiently conduct electricity and operate at a lower temperature. There is also a need for a meter socket that can use a single connector to make connections of 45° or 90° with respect to the centerline of the meter socket.
The present invention is directed to overcoming each of the disadvantages set forth above as well as other disadvantages not specifically described herein but which will become readily apparent to those of ordinary skill in the art in view of the detailed description of the present invention.
Thus, it would be desirable to provide a watthour meter socket that has a simplified construction, uses fewer components and requires fewer manufacturing steps. It would also be desirable to provide a watthour meter socket adapter with stand-alone support blocks that can be attached without screws or fasteners. It would also be desirable to provide a watthour meter socket adapter designed to fixedly receive a jaws assembly so that it stayed in position when the connector retaining screws are tightened. It would also be desirable to provide a watthour meter socket adapter having a connector that has only one hole for increased efficiency and that can be mounted to the meter socket mounting block at different angles.